Waltham, Massachusetts
Waltham is a city in Middlesex County, Massachusetts, with 65,218 residents in 2020. It is in Massachusetts's 5th congressional district. It spans 2 state house districts. Its state senate district is Third Middlesex District.
County
| County | Share of residents |
|---|---|
| Middlesex County | 100% |
Congressional district
| Congressional district | Share of residents |
|---|---|
| Massachusetts's 5th congressional district (MA-05) | 100% |
Elected officials
| Office | Member | Contact | Share of residents |
|---|---|---|---|
| Mayor | Jeannette A. McCarthy | 781-314-3100 | citywide |
| U.S. Representative (MA-05) | Katherine M. Clark (D) | 202-225-2836 | 100% |
| U.S. Senator | Edward J. Markey (D) | 202-224-2742 · contact form | statewide |
| U.S. Senator | Elizabeth Warren (D) | 202-224-4543 · contact form | statewide |
| State Senator (Third Middlesex District) | Mike Barrett (Democratic) | 100% | |
| State Representative (9th Middlesex District) | Tom Stanley (Democratic) | 67% | |
| State Representative (10th Middlesex District) | John Lawn (Democratic) | 33% |
Officials serving now (members of Congress until January 3, 2027). Sources: Mayors: Open States (public domain); State legislators: Open States (public domain); Members of Congress: the @unitedstates project, congress-legislators (CC0).
Local government
- Waltham website: https://www.city.waltham.ma.us/
- Waltham laws: search for the Waltham, Massachusetts code of ordinances
- Middlesex County laws: search for the Middlesex County, Massachusetts code of ordinances
State legislative districts
| State senate district | Share of residents |
|---|---|
| Third Middlesex District | 100% |
| State house district | Share of residents |
|---|---|
| 9th Middlesex District | 67% |
| 10th Middlesex District | 33% |
ZIP codes
Percentages mark ZIPs only partly in Waltham: the share of that ZIP's residents living in it.
Get this in your AI agent
Your agent can get Waltham's counties and districts with shares, its ZIP codes (level='zcta'), and its boundary as GeoJSON (get_boundaries). Add https://boundarymcp.com/mcp to Claude, ChatGPT, Cursor or Codex (free, no key; how), then:
related_geographies(id="us:place:2572600")
Waltham here is the Census Bureau's place boundary as of January 1, 2025. Shares are of 2020 Census population. Districts are the maps in force for the November 3, 2026 election.